A complete guide to international calibration standards

When organising the calibration of measurement equipment for engineering, quality managers must ensure they are being guided by the right calibration standards. Many of these standards are internationally recognised, with businesses needing to adhere to them to provide the necessary quality standards for their customers. In some industries, failure to prove compliance can seriously affect a business’ ability to trade.

But what exactly are calibration standards, how should quality managers know which standard their equipment needs to be calibrated to and what are some of the most important international calibration standards?

What are calibration standards?

Calibration standards are a documented set of requirements and guidelines that are used to guide calibration and ensure instruments are fit for purpose. Requirements for calibration are often part of much larger standards for quality management (e.g. ISO 9001).

Adhering to calibration standards and being able to prove this with a documented trail of evidence is vital for safety, your ability to prove the quality of products or services, and even your ability to trade legally. Having instruments calibrated to a defined standard displays that they are provably accurate and have been calibrated in an environment that ensures this. For instance, for equipment to be calibrated to ISO 17025 standard, it must be processed in a laboratory accredited to this standard.

What standard does my equipment need to be calibrated to?

The standard your business’ instruments need to be calibrated to will depend on a number of factors to do with the type of product or service the equipment is used to produce or provide. These will usually depend on industry; some industries like aerospace and medicine have their calibration standards set by trade bodies because of how crucial accuracy is to safety.

ISO 9001 calibration

ISO 9001 is the international standard that sets requirements for organisations’ quality management systems (QMS). ISO 9001 specifies its stipulations on calibration in clause 7.1.5 in a section called Monitoring and Measuring Resources - which should be considered the minimum guidelines for calibration of any equipment. ISO 9001’s calibration requirements are relatively broad, stating that:

• Organisations must ensure the instruments they use are suitable for the measurement activities they are needed for.
• These instruments must be maintained to ensure their continued adequacy for use.
• Measuring equipment must be calibrated at specified intervals against standards traceable to national or international standards.
• Organisations must protect instruments against damage or adjustments that would invalidate their calibration status, and declare any such adjustments if they are found.

ISO 17025 calibration

ISO 17025 is a specific standard detailing requirements for the technical competency of calibration laboratories. ISO 17025 shares many of the same principles as ISO 9001, however goes much further, and focuses more closely on management structure and processes in a calibration lab. ISO 17025 also requires traceability of measurements and application of measurement uncertainty.

An ISO 17025 audit covers factors including the training level of laboratory personnel, calibration equipment used and environmental factors (e.g. temperature). Organisations choosing a calibration service with ISO 17025 accreditation can be confident their equipment will be calibrated with a high standard of competence and to a high degree of accuracy.

AS 9100 calibration

AS 9100 is a quality management system for the aerospace industry, and builds upon ISO 9001 requirements. According to NQA, the standard applies to organisations that “design, develop or provide aviation, space and defence products and services, including parts, components and assemblies”.

AS 9100 includes aerospace-specific guidelines for safety in the development and production of parts. Therefore, measurement equipment is subject to a greater level of scrutiny than in many other industries.

MIL-STD-45662 calibration

MIL-STD-45662, created by the US Department of Defence, was one of the first standards specific to calibration. Despite being discontinued in 1995, MIL-STD-45662 continues to be relevant to organisations in the military and civilian sectors today given it laid the foundations for other standards including ISO 17025.

However, in some aspects, ISO 17025 does not go as far. For instance, MIL-STD-45662 sets out the maximum collective uncertainty as no more than 25%, whereas ISO 17025 doesn’t establish a limit. While organisations can no longer be accredited to MIL-STD-45662 standard, many continue to calibrate their instruments according to its guidelines.

IATF 16949 calibration

IATF 16949 addresses calibration in the automotive industry. Like AS 9100, IATF 16949 is built on ISO 9001, but also includes requirements that are specific to the automotive industry. According to NQA, “IATF 16949 emphasises the development of a process oriented quality management system that provides for continual improvement, defect prevention and reduction of variation and waste in the supply chain”.

The IATF itself is a group of manufacturers and trade associations that exists to improve the quality of automotive products globally, while the calibration requirements of IATF 16949 are applicable to any company in the automotive supply chain.

ISO 13485 calibration

Organisations manufacturing medical devices or providing medical-related services have their calibration requirements set out by ISO 13485. These include companies that develop, produce, distribute, install or service medical devices. However, unlike many other industries, organisations involved with medical devices must meet industry-prescribed regulations (e.g. the EU Medical Device Directive). Adopting ISO 13485 as their calibration strategy allows these organisations to be better prepared to meet such regulations.

UKAS accredited calibration services from DM Systems & Test

DM Systems & Test are certified to carry out equipment calibration to all major quality standards thanks to our United Kingdom Accreditation Service (UKAS) certification - demonstrating the high level of technical competence in our labs and among our technicians.

Our expert engineers are trained to the highest levels on mechanical and electrical equipment used in specialist industries including pharmaceutical, aerospace and defence. Our laboratory facilities are state of the art and are operated and maintained for ultimate accuracy and consistency.

To learn more about how we can take care of your organisation’s calibration requirements, no matter how complex or what industry you are in, contact our team today.